Aldehyde IR spectra exhibit distinct peaks due to the presence of the aldehyde group. The C-C stretching vibration appears as a strong band in the 1680-1730 cm-1 region. CH2 and CH3 bending vibrations also contribute to the spectrum. The aldehyde proton gives rise to a characteristic peak around 2720-2820 cm-1 due to its resonance with the carbonyl group. These vibrational modes provide valuable information for identifying and analyzing aldehydes using infrared spectroscopy.